Thread protectors



May 29, 1956 .1. WALDEN THREAD PROTECTORS Filed May 2'7, 1955 I e? f.

. INVENTOR (10km Valdem BY WW O 1a,,.,,,,,,,,unnnuj ATTORNEYS UnitedStates Patent THREAD PROTECTORS John Walden,.SanAngelo, Tex.

- Application May 27,1953, serialNoi 357,864

:7 Claims. 01. 138-96) This invention relates to caps, or protectors,-which may befitted-oven the end of a pipe having external threads toprotect the threads against damage while the pipe is being handled. V

In well working, particularly in the oil field, sections of pipe havetobe raised to -avertical position for lowering into the well. This isusually accomplished by fastening a cable to one end. In hoistingthe'pipe-the lower end is dragged over the ground and, unless protected,the threads are damaged. It has been the custom to thread a cap over thethreaded lower end, but the cap is difiicult to remove, and if itcatches upon a projection while thepipe is being lifted, the cable isapt to break and the pipe fall, jeopardizing the lives of workmen. f Theprincipal object of the. present-invention is to provide a threadprotector for pipe which can be placed upon, and removed from, pipequickly and with minimum .eifort.

A further :object is to provide a protector whichwill be stripped fromthe pipe before damage can result in the event the protector-shouldcatch upon the derrick platform or other obstacle.

A more specific object is to provide a device of this nature which willengage the pipe threads by friction only, with means for releasing itsfrictional hold on the pipe for removal from the pipe.

Another object is the provision of a protector which may be manufacturedat low cost, and yet will be reuseable over long periods of time.

Other objects of the invention will become apparent from the followingdescription of one practical embodiment thereof, when taken inconjunction with the drawings which accompany, and form part of, thisspecification.

In the drawings:

Figure 1 is a perspective view of one end of a length of pipe with aprotector embodying the principles of the present invention in placecovering the threaded portion thereof;

Figure 2 is an end view of the protector in closed, or thread-gripping,position;

Figure 3 is a view similar to Figure 2 showing the protector in openposition for placing upon, or removing from, a pipe end; and,

Figure 4 is a longitudinal section through the protector in place upon apipe end, and is taken upon the line 44 of Figure 2.

In general, the invention comprises a longitudinally split, spring steelsleeve with means for spreading the sleeve to enlarge its diameter topermit slipping it over a pipe end, which, when released, willfrictionally grip the pipe to firmly hold it upon the pipe end.

Referring to the drawings in detail, there is shown a thread protector 1which may be placed upon the end of a section of pipe 2 having externalscrew threads 3. The protector consists of a longitudinally split sleeve4 of spring steel. The cylindrical curvature of the spring steel sleevehas been pre-set so that in its normal unice sprung position the ends 5and Get the sleeve :will overlap one another an appreciable distance, asshown in Figure 2. The bottomedge of the sleeve is rolled over-to form ahead 7 to add rigidity to the sleeve and to -prevent injury to workmenin handling the device.' Because of the overlapping of'the end sectionsof thesleeve, the bead is discontinued in the: overlapping area. Becauseof this rolled head, the upper portion of the sleeve will expand agreater distance when the sleeve is spread, so that the upper,orleading, end of the sleeve will -flare slightly outwardly tofacilitate 'placing the sleeve over the end of apipe.

The sleeve nearits lower end is bridged by two normally abuttingspreader plates 8 and 9I These plates are of-less' width than 'thediameter of the sleeve and their outer edges are arcuate to conformtothe wall of the cylindrical sleeve. The plates aresecured to the wallsof the sleeve by'Welding-along these arcuate edges. Plates lie in thesame-horizontal plane, and their confronting edges are in substantialabutment-when the cylinder is in its normal, unsprung condition. 'Theconfronting edges ofthe plateshave companion arcuate'recesses l0 and 11which, when the' plates are in abutting relation, form a pear-shapedopening.

The cylinder is caused to spread and to be released by means of a;cam.12 which is of the same shape as the openingiormedzbyxthe recesses 10and 11- and of the same: thickness. as' the. spreader plates 8 and 9.Thus the 'camzwilluexactly fit the opening when the'cylinder isinitstunsprungpposition. Cam.12 is provided with a= square aperturelS-inorder to receive an operating handle-14.v Handle 14 has a squareishank 15 .which :fits within the opening 13 in the cam to rotate thecam when the handle is'moved. 'The handle also has a stud-16.projecting:,beyond the square shank which is cylindricaland-.screwrthreaded. A circular flange 17 of larger diameter than thewidth of the opening formed by the recesses in the spreader plates isprovided on the handle to bear against one side of the spreader platesto prevent the handle from moving through the opening. A Washer 18 isslipped on the stud 16 on the opposite side of the spreader plates, anda nut 19 is threaded onto the stud to lock the assembly in position.Washer 13 may be similar in shape to the opening formed by the recessesin the plate, but of larger dimensions to prevent the handle pullingthrough the opening. If desired, stud 16 may be apertured and a cotterpin 20 passed through the aperture to lock nut 19 in position on thestud.

When handle 14 is rotated in either direction, cam 12 will bear upon thearcuate surfaces of the opposing recesses 10 and 11 in the spreaderplates and force the plates apart. This motion will be transmitted bythe plates to opposite sides of the cylindrical sleeve and cause thesleeve to spread to enlarge its diameter. The overlapping of the ends 5and 6 of the sleeve is willcient so that these ends will remain inoverlapping relation when the sleeve is spread to its maximum extent.When in this position the sleeve will slip freely over the end of thepipe which is to be protected, and when the handle is moved back to itsposition of rest, the inherent resiliency of the spring steel sleevewill cause the sleeve to contract about the end of the pipe tofrictionally engage the pipe end. If desired, the interior surface ofthe sleeve between the spreader plates and the top edge thereof may belined with rubber or other resilient gripping material to facilitateobtaining a tight gripping upon the pipe end. The threads on the end ofthe pipe will compress the resilient lining and hold against accidentallongitudinal movement of the sleeve. Even though the grip of theprotector on the pipe is quite firm and serves to hold the protectoragainst accidental displacement, the sleeve will be readily strippedfrom the end of the pipe if it should catch on a projection while thepipe is being moved It will be obvious that when the portector hasserved its purpose, movement of the handle will release its grip uponthe pipe end and it may be removed for reuse at a later time.

While in the above, one practical embodiment of the invention has beendisclosed, it will be understood that the specific details ofconstruction described and illustrated are merely by way of example, andthat various changes may be made within the scope 'of the appendedclaims.

What is claimed is: p

l. A protector for externallythreaded pipe ends comprising, a springsteel longitudinally split sleeve, spreader plates attached along oneedge to the side Wall of said sleeve near one end thereof and onopposite sides of the split in said sleeve, said plates lying in acommon plane and having their confronting edges in substantial abutmentwith one another when the sleeve is-in its normal unsprung position,said plates having companion and opposite recesses in the confrontingedges thereof to form an opening, a cam seated in said opening, andmeans to rotate said cam to spread said sleeve.

2. In a protector for externally threaded pipe ends as claimed in claim1, a lining of resilient material on the inside of said sleeve tocontact the threads of a pipe when the protector is upon the pipe.

3. A protector for externally threaded pipe ends comprising, a springsteel longitudinally split sleeve, spreader plates attached along oneedge to the side wall of said sleeve near one end thereof and onopposite sides of the split in said sleeve, said plates lying in acommon plane and having their confronting edges'in substantial abutmentwith one another when the sleeve is in its normal unsprung position,said plates having companion and opposite recesses in the confrontingedges thereof to form an opening, a cam seated in said opening, and ahandle connected to said cam to rotate said cam to force the spreaderplates apart and spread said sleeve.

4. In a protector for externally threaded pipe ends as claimed in claim3, said opening being pear-shaped, and said cam'being of such size andshape as to exactly fit said opening.

5. A protector for externally threaded pipe ends comprising, a springsteel longitudinally split sleeve, spreader plates attached along oneedge to the internal side wall of said sleeve near one end thereof andon opposite sides of the split in the sleeve, said spreader plates lyingin the same plane and having confronting edges in substantial abutmentwith one another when the sleeve is in its normal unsprung position,said plates havingcompanion recesses in the confronting edges thereof toform an opening, a cam of the same shape and size as said opening seatedtherein, said cam having a square hole therein, a handle having aportion to bear against one side of said spreader plates and asquareshank seated in said hole in said cam, a stud projecting from saidshank, a washer on the shank, and means to lock the handle and cam inassembled relation.

6. In a protector for externally threaded pipe ends as claimed in claim5, said opening being pear-shaped.

7. In a protector for externally threaded pipe ends as claimed in claim5, a lining of resilient material on the inside of said sleeve tocontact the threads of a' pipe when the protector is upon a pipe.

References Cited in the file of this patent UNITED STATES PATENTSHolland Aug. 15, 1935

